There are more than 50,000 species of fungi. Fewer than 100 are pathogenic to humans. However, more than 10,000 fungi cause disease in plants. Fungal pathogens are extremely costly pests, affecting a broad range of crop plants. It is estimated that anywhere between 20–30% of crop production is lost to fungal pathogens alone worldwide with the greatest losses outside the United States (FAO Report). Losses from fungal pathogens are realized in every stage of crop production ranging from those fungi that attack seeds or germinating seed to those that attack the stems of seedlings, the roots, stems, vascular system, fruits and leaves of mature crops.
There are presently a number of widely used fungicide products on the market, including triazoles, anilides, dithiocarbamates, and benzimidazoles. Total worldwide sales of fungicides in 1995 approached $60 billion with greater than 80% of the market being non-U.S.
Essentially all of the non-biological fungicides are toxic chemicals to the fungi, as well as to the environment when they enter drinking water supplies and natural waters and can be toxic to animals and humans through accidental contact. In addition, many of the chemicals generate resistance in the target organisms.
Biological control is based on inhibition by some microorganisms on the growth and action of pathogenic fungi, which cause rotting (See for example, U.S. Pat. No. 4,975,277 and EP 0 781 843 A1). However, there can be great variations in the antifungic activity of different isolates or strains of the same species. In addition, the effectiveness of various strains may be diminished during storage and harvesting.